Everybody noticed how hot July was. According to NASA, it was the hottest July ever recorded, going back as far as we’ve been recording temperatures and other weather data (about 200 years or so). Not only that, but this year is on track to be the hottest year ever recorded—which is par for the course of late, as 14 of the 15 hottest years recorded have happened since 2000. That’s an obvious trend, and one which we need to keep an eye on, because it isn’t going to get better.

At least, it won’t get better if we don’t step up and start taking better care of the Earth.

Any guesses why it’s been so hot? Yup: climate change, caused primarily by greenhouse gas emissions caused, of course, by human activity. The world is getting hotter and it’s going to have a lot of negative affects on us.

What does this have to do with gardening? A lot.

Firstly, the number of days that will break 95 degrees in the United States, which was pretty low between 1991 and 2010, will be going up precipitously over the rest of the century. A couple of key American cities illustrate this point. Between 1991 and 2010, Boston averaged 1 day over 100 degrees per year, as did Chicago, while Washington D.C had 4, Atlanta 7, and Dallas 44. By 2060, those numbers should jump to Boston: 9, Chicago: 23, Washington D.C.: 32, Atlanta: 47, and Dallas: 97. By 2100, we’re looking at Boston: 28, Chicago: 54, Washington D.C.: 74, Atlanta: 94, and Dallas: 133 days a year. Dallas should be spending about four months a year over 95 degrees.

It’s going to be more difficult to work or play outside in the summer, but that’s just the beginning. Those temperatures are also going to affect water supplies, stifle the growth of certain crops (and move whole parts of the country and the world into new hardiness zones), and lead to even more forest and brush fires in the American West.

The continuing warming trend isn’t just bad for us as urban gardeners; it’s bad for the world at large. It’s up to us to add our voices to the chorus demanding action on climate change, before it’s too late.